1. Field of the Invention
The present invention relates generally to direct current power supplies for driving large current loads and more specifically to power supplies including a battery backup that can be charged.
2. State of the Art
Automatic doors are implemented in various configurations such as, for example, sliding doors, rotating panel doors, folding doors, and revolving doors. Automatic doors are often relied on for security and fire safety purposes. For example, an automatic door system including one or more accordion-type doors may be used as a security and/or a fire door. These automatic doors are configured to open or close automatically dependent on a trigger such as a security or fire indicator. As a result, the automatic doors include control electronics and one or more motors to control movement of the door. This motor and accompanying control electronics must be driven by a power supply. Many automatic doors include a conventional power supply coupled to a traditional Alternating Current (AC) power source that converts the AC supply to a Direct Current (DC) supply suitable for use by the motor and control electronics.
However, in many emergency situations, a reliable AC power source may not be available. To provide reliable power, many automatic doors include a conventional AC/DC converter power supply coupled with a battery backup that switches in when the AC power source is compromised. Furthermore, in some cases, the power source for the automatic door may include a battery charger for maintaining the battery at a full charge via AC/DC converter power supply.
A need exists to provide a more reliable and efficient power source that can provide power from a conventional AC source as well as a battery backup to provide power for a motor and accompanying control electronics of an automatic door.